"In respecting the due process of several investigations and in not wanting to preempt the outcome of those inquiries, we cannot offer any comment regarding the circumstances of the accident and we would ask that the privacy of all concerned be respected at this very difficult time."

Today investigators are returning to the wreckage to start to piece together what could have gone wrong.

WATCH: Hear from the rescue crewmen who responded to yesterday's crash

Rescue mission for fatal plane crash :
Helicopter rescue air crewmen from RACQ Capricorn Helicopter Rescue Service's Dave Patterson and RACQ LifeFlight's John Kennedy share what it was like being involved in the mission to rescue four people involved in a plane crash today.

UPDATE Tuesday 6pm:

THE Australian Transport Safety Bureau is investigating today's fatal plane crash which involved a Cessna 172M near Agnes Water.

It is reported the aircraft collided with terrain and came to rest inverted, resulting in substantial damage

In a statement the ATSB said, "The ATSB has deployed two investigators-specialising in aircraft engineering and operations-to the accident site."

"While on site, the investigators will survey the site, examine the wreckage, talk to witnesses and review aircraft and pilot documentation.

"They are expected to be onsite for three days."

One woman died at the scene however three patients were transported to Rockhampton and Bundaberg Hospital.